The main objective of the proposed research is to develop through the study of the properties of ribonucleotide reductase, a rational approach for the design of specific and potent, irreversible inhibition of this enzyme. BIBLIOGRAPHIC REFERNECES: Cory, J.G., "Ribonucleotide Reductase in Mammalian Cells and Its Relationship to DNA Synthesis", Medikon 4, 5 (1975). Cory, J.G. and Mansell, M.M., "Studies on Mammalian Ribonucleotide Reductase Inhibition by Pyridoxal Phosphate and the Dialdehyde Derivatives of Adenosine, AMP and ATP", Cancer Res. 35, 390 (1975).